A neurotransmitter is a chemical messenger that transmits signals between nerve cells, or neurons, in the brain and throughout the body. When a neuron receives a signal, it releases neurotransmitters into the synapse, the gap between neurons. These chemicals bind to receptors on the next neuron, allowing the signal to continue its journey. Common neurotransmitters include serotonin, which affects mood, and dopamine, which plays a role in pleasure and reward. Neurotransmitters are essential for many bodily functions, including movement, memory, and emotions. Imbalances in neurotransmitter levels can lead to various health issues, such as depression or anxiety. Understanding how these chemicals work helps researchers develop treatments for mental health disorders and other neurological conditions.